Fiber optic ribbon cable assembly and method of manufacturing same

Abstract

A fiber optic ribbon cable assembly has optical connector assemblies manufactured in line with the ribbon cable assembly so as to provide a fixed, lateral spacing of the optical fibers relative to each other within the connector assembly and has the remaining portion of the fiber optic ribbon cable manufactured within an arbitrary lateral spacing of the optical fibers relative to each other. A pair of adhesive tape layers are sandwiched around the optical fibers and the in-line optical connector assemblies. By having the connector assemblies manufactured in line with the fiber optic ribbon cable, resulting ribbon cable assembly is easier to manufacture, has a higher alignment accuracy, and is more cost effective than existing techniques for manufacturing ribbon cable assemblies.

We claim: 
     
       1. A fiber optic ribbon cable assembly comprising: a pair of adhesive tape layers;   a plurality of optical fibers arranged in a generally longitudinal orientation between the pair of adhesive tape layers with adjacent optical fibers positioned with an arbitrary lateral spacing relative to each other; and   at least one connector assembly having at least a portion thereof disposed between the pair of adhesive tape layers and having the plurality of optical fibers disposed therein with adjacent optical fibers positioned with a fixed lateral spacing relative to each other.   
     
     
       2. The ribbon cable assembly of claim 1 wherein the arbitrary lateral spacing ranges from 0.0 to 2.0 cm. 
     
     
       3. The ribbon cable assembly of claim 1 wherein the pair of adhesive tape layers include an encapsulating layer and are the outermost jacket for the ribbon cable assembly. 
     
     
       4. The ribbon cable assembly of claim 1 wherein each of the pair of adhesive tape layers includes a pair of margin portions that extend laterally beyond a planar orientation of the plurality of optical fibers and wherein the pairs of margin portion are adhered to each other to form a seal along at least a portion of each of a longitudinal edge of the ribbon cable assembly. 
     
     
       5. The ribbon cable assembly of claim 1 wherein the pair of adhesive tape layers are each comprised of an outer protective member, an intermediate adhesive layer, and an inner encapsulating layer. 
     
     
       6. The ribbon cable assembly of claim 5 wherein one layer of material comprises both the intermediate adhesive layer and the inner encapsulating layer. 
     
     
       7. The ribbon cable assembly of claim 5 wherein the protective member is comprised of a material selected from the set of: plastic, metal, fabric or any combination thereof, the intermediate adhesive layer is comprised of a material selected from the set: of pressure sensitive adhesive, thermoset adhesive, thermoplastic adhesive, radiation-curable adhesive, mechanically interlocking structures or any combination thereof, and the inner encapsulating layer is comprised of a material selected from the set of: pressure sensitive adhesive, thermoset adhesive, thermoplastic adhesive, radiation-curable adhesive, gel, foam, fibrous material, deformable plastic or any combination thereof. 
     
     
       8. The ribbon cable assembly of claim 1 wherein the optical fibers each comprise a fiber optic core comprised of a material selected from the set of: glass, plastic or air, the fiber optic core being surrounded by an optical cladding layer comprised of a material selected from the set of: glass, plastic or metal. 
     
     
       9. The ribbon cable assembly of claim 8 wherein the optical fibers further include a buffer layer surrounding the optical cladding layer, the buffer layer comprised of a material selected from the set of: plastic, metal, carbon, ceramic or any combination thereof. 
     
     
       10. The ribbon cable assembly of claim 1 wherein the connector assembly comprises an upper connector component and a lower connector component, at least one of which includes structure for separating adjacent optical fibers into the fixed lateral spacing. 
     
     
       11. The ribbon cable assembly of claim 10 wherein each of the connector components includes at least a pair of laterally-oriented structures on an outer surface of the component that define a longitudinal center portion therebetween from which the pair of adhesive tape layers are removed. 
     
     
       12. The ribbon cable assembly of claim 10 wherein each of the connector components includes a longitudinal center portion which is cut generally perpendicular to the longitudinal orientation of the optical fibers subsequent to disposition of the connector assembly within the pair of adhesive tape layers to expose ends of the plurality of optical fibers which are disposed within a lateral cross-section of the connector assembly in the fixed lateral spacing. 
     
     
       13. The ribbon cable assembly of claim 10 wherein each of the connector components includes a longitudinal first half and a longitudinal second half such that the connector assembly comprises four pieces and the optical fibers are cut generally perpendicular to their longitudinal orientation subsequent to disposition of the connector assembly within the pair of adhesive tape layers between the first halves and second halves. 
     
     
       14. The ribbon cable assembly of claim 10 further comprising means for joining the connector components. 
     
     
       15. The ribbon cable assembly of claim 1 wherein the connector assembly includes a longitudinal center portion which is cut generally perpendicular to the longitudinal orientation of the optical fibers subsequent to disposition of the connector assembly within the pair of adhesive tape layers to expose ends of the plurality of optical fibers which are disposed within a lateral cross-section of the connector assembly in the fixed lateral spacing. 
     
     
       16. The ribbon cable assembly of claim 1 wherein the connector assembly includes at least a pair of laterally-oriented structures on at least one outer surface of the connector assembly that define a longitudinal center portion therebetween from which one of the pair of adhesive tape layers is removed. 
     
     
       17. The ribbon cable assembly of claim 16 wherein the structures include means for severing the adhesive tape layer during manufacture of the ribbon cable assembly. 
     
     
       18. The ribbon cable assembly of claim 1 wherein the connector assembly includes structure for separating the optical fibers such that the optical fibers are arranged in a non-planar configuration. 
     
     
       19. The ribbon cable assembly of claim 18 wherein the connector assembly includes at least two separate rows of grooves having different depths so as to position the optical fibers in a staggered lateral configuration. 
     
     
       20. The ribbon cable assembly of claim 18 wherein the connector assembly comprises a pair of connector components each having an inner and outer component with a semi-circular cross-sectional shape and at least one of which has grooves along an inner surface into which the optical fibers are disposed. 
     
     
       21. A method of manufacturing a fiber optic ribbon cable assembly comprising the steps of: (a) providing a plurality of optical fibers oriented in a generally longitudinal orientation;   (b) arranging adjacent ones of the plurality of optical fibers in a fixed lateral spacing relative to each other;   (c) applying a connector assembly onto a first longitudinal segment of the plurality of optical fibers;   (d) sandwiching at least a second longitudinal segment of the plurality of optical fibers separate from the first longitudinal segment between a pair of adhesive tape layers to form a ribbon cable assembly having adjacent ones of the plurality of optical fibers maintained in an arbitrary lateral spacing relative to each other in the second longitudinal segment.   
     
     
       22. The method of claim 21 wherein step (a) is a continuous process of feeding the plurality of optical fibers from a corresponding plurality of spools of continuous optical fibers. 
     
     
       23. The method of claim 22 wherein an entire length of the ribbon cable assembly, including both the first and second longitudinal segments, is sandwiched between the pair of adhesive tape layers in step (d). 
     
     
       24. The method of claim 21 wherein step (d) is accomplished using at least a pair of rollers to compress the pair of adhesive tape layers together. 
     
     
       25. The method of claim 21 wherein step (b) is accomplished by passing the plurality of optical fibers through a fiber guide. 
     
     
       26. The method of claim 21 wherein steps (b) and (c) are accomplished simultaneously by providing structure within the connector assembly that defines the fixed lateral spacing. 
     
     
       27. The method of claim 21 wherein the connector assembly comprises an upper connector component and a lower connector component and wherein step (c) is accomplished by sandwiching the plurality of optical fibers between the upper connector component and the lower connector component. 
     
     
       28. The method of claim 27 wherein at least one of the connector components includes structure for separating adjacent optical fibers into the fixed lateral spacing and steps (b) and (c) are accomplished simultaneously. 
     
     
       29. The method of claim 27 wherein each of the connector components includes structure defining a longitudinal center portion and wherein the method further comprises the step of: (e) cutting the center portion of the connector components generally perpendicular to the longitudinal orientation of the optical fibers to expose ends of the plurality of optical fibers which are disposed within a lateral cross-section of the connector assembly in the fixed lateral spacing.   
     
     
       30. The method of claim 27 wherein each of the connector components includes a longitudinal first half and a longitudinal second half such that the connector assembly comprises four pieces and wherein the method further comprises the step of: (e) cutting the optical fibers generally perpendicular to their longitudinal orientation between the first halves and second halves of the connector components.   
     
     
       31. The method of claim 27 wherein step (c) includes the step of joining the connector components together by using a technique selected from the set comprising: adhering the connector components together, mechanically interlocking the connector components together, welding the connector components together, or any combination thereof. 
     
     
       32. The method of claim 21 wherein the connector assembly includes at least a pair of laterally-oriented structures on at least one outer surface of the connector assembly that define a longitudinal center portion therebetween and wherein the method further comprises the steps of: (e) removing the pair of adhesive tape layers from the center portion; and   (f) cutting the center portion generally perpendicular to the longitudinal orientation of the optical fibers to expose ends of the plurality of optical fibers which are disposed within a lateral cross-section of the connector assembly in the fixed lateral spacing.   
     
     
       33. The method of claim 32 wherein step (e) is accomplished in part by the structures being provided with an edge for severing the adhesive tape layer during step (d). 
     
     
       34. The method of claim 21 wherein each of the pair of adhesive tape layers includes a pair of margin portions that extend laterally beyond a planar orientation of the plurality of optical fibers and wherein the method further comprises the step of: (e) adhering the pairs of margin portions to each other to form a seal along at least a portion of each of a longitudinal edge of the ribbon cable assembly.   
     
     
       35. The method of claim 21 wherein the connector assembly includes a longitudinal center portion and wherein the method further comprises the step of: (e) cutting the center portion generally perpendicular to the longitudinal orientation of the optical fibers to expose ends of the plurality of optical fibers which are disposed within a lateral cross-section of the connector assembly in the fixed lateral spacing.   
     
     
       36. The method of claim 21 wherein step (b) arranges the optical fibers in a non-planar configuration. 
     
     
       37. The method of claim 21 wherein the adhesive tape layers include an encapsulating layer and wherein step (d) does not include additional jacketing applied to the fiber optic cable assembly in order to protect the fiber optic cable assembly.